The present invention relates to an inverting mechanism for inverting the cope of a molding flask to facilitate repairing and cleaning thereof.
Casting is a process used to produce complex parts. A molten metal or alloy is caused to flow into a mold cavity and permitted to solidify. There are four common casting processes characterized by the mold material used, the method for flowing the molten metal into the mold cavity, and the method used to shape the mold cavity. The four casting processes are sand casting, investment casting, permanent mold casting, and die-casting.
Sand casting is the production of metal castings in sand molds. Investment casting is production of a casting in a mold obtained by enclosing an expendable pattern with a heat resisting material such as ceramic, to produce a shell. The expendable pattern may consist of wax, plastic, or other material and is removed prior to filling the mold with liquid metal. In permanent mold casting, molten metal is poured directly into mold cavities cut in metals, alloys, or graphite molds. Permanent mold casting is used for the production of many castings of the same form. Die-casting involves the injection of molten metals into a mold cavity at high pressure. Die-casting is typically limited to the casting of non-ferrous metals.
In sand casting, the molds are generally formed in molding frames or flasks. The molding flask is typically a metal frame. The upper part of the molding flask is known as the cope and the bottom half is the drag. Depending upon the complexity of the mold, additional segments may be required between the drag and cope called the cheek. Together, these molding flask parts form the periphery of the pattern for the cast part. Cores may be required to form internal cavities in the casting.
Molten metal is typically introduced through a sprue hole in the cope to run into the casting cavity. Once the metal has been permitted to harden, the molding flask is separated at parting lines that correspond to the separation between the cope and drag portions. The cast part can then be removed for further machining and other processing to form the finished part.
Once the cast part has been removed from the flask, it is necessary to clean and/or repair the pattern before casting the next part. Cleaning of the drag simply involves positioning the drag on the floor and performing the necessary work. For the cope, the cleaning and repair process may involve suspending the cope from a crane to permit workers to access the open pattern underneath and perform the necessary work. Having workers positioned under a suspended cope presents numerous safety concerns. Serious injury could result if chains or other suspension members failed and permitted the cope to fall. Cleaning and repair is also made difficult due to the workers having to perform the work above their heads on the suspended cope.
An object of the invention is to produce a mechanism for inverting the cope of a molding flask wherein efficiency of the cleaning and repair process is maximized.
Another object of the invention is to produce a mechanism for inverting the cope of a molding flask wherein the cope is fixedly supported to minimize the potential for injury to workers.
Another object of the invention is to produce a mechanism for inverting the cope of a molding flask wherein the labor required for cleaning and repairing the cope is minimized.
The above, as well as other objects of the invention, may be readily achieved by a mechanism for inverting the cope of a molding flask comprising: a frame including spaced apart ground engaging members and cooperating upstanding supports; a guide member having a longitudinal axis and supported by the frame; at least two support arms, each of the arms having a proximal end and a distal end, the proximal ends of the arms being mounted to the guide member and adapted to slide toward and away from one another and to pivot about the longitudinal axis of the guide member, and the distal ends adapted to pivotally receive the cope of a molding flask; a cope grasping member affixed to at least one of the arms between the proximal and distal ends thereof; and a driver for imparting movement to at least one of the arms to move the arms toward or away from one another.